Summary

The purpose of this study is to find out whether short term treatment with a
antihypertensive medication prazosin, can influence the levels of a dopamine in the brain.
We will examine the levels of dopamine in the the brain using Positron Emission Tomography
(PET) and Magnetic Resonance Imaging (MRI). We hypothesize that there will be no significant
changes in dopamine levels in healthy individuals taking prazosin.

Study Design

Gradual upward titration to 15mg/day (or highest dose tolerated) for approximately three weeks.

prazosin hydrochloride
Teva-Prazosin

Gradual upward titration to 15mg/day for approximately three weeks.

Primary Outcomes

Measure

Changes in [11C]-(+)-PHNO binding

time frame:
0, 3 weeks, 1 week washout

Eligibility Criteria

Male or female participants from 19 years up to 45 years old.

Inclusion Criteria:
- Healthy males and females of any ethnic origin between 19 and 45 years old
Exclusion Criteria:
- Use of any illicit drugs in past 3 months prior to randomization and/or have a
current or past diagnosis of drug abuse/dependence (including alcohol)
- Current or past DSM-IV diagnosis of any Axis I psychiatric disorder
- Major psychiatric illness and/or substance dependence in first order relatives
- Current active or past suicidal ideation
- Baseline systolic blood pressure outside the normal range
- Current use of medications that could interact with prazosin (e.g. beta blockers,
phosphodiesterasetype 5 inhibitors, indomethacin, verapamil, modafinil, clonidine)
- Current use or use during the previous month of medication that may affect the CNS at
the time of scanning (e.g. neuroleptics, bupropion)
- Any significant abnormalities in baseline blood results (e.g. CBC, renal and hepatic
indicators) or ECG readings that would preclude the use of prazosin
- Pregnancy, trying to become pregnant or breastfeeding
- Presence of metal objects in the body (e.g. some artificial joints, bone pins,
surgical clips, skull plate, certain part of dental braces) or implanted electronic
devices (e.g. cardiac pacemaker, neurostimulator), that preclude safe MR scanning
- Claustrophobia
- Participation in any nuclear medicine procedures that, including the dose received
during participation in this study, will bring the total radiation dose over the
currently approved guideline of 20mSv in a 12-month period
- Cardiovascular or cerebrovascular diseases
- History of or current neurological illnesses including seizure disorders, migraine,
multiple sclerosis, movement disorders, head trauma, CVA or CNS tumor
- Abnormal body mass (defined as not within 20% of normal BMI
- Learning disability, amnesia or other conditions that impede memory and attention

Additional Information

Official title

Exploring the Effects of Prazosin on Basal Dopamine in Healthy Humans: A [11C]-(+)-PHNO PET Pilot Study

Principal investigator

Bernard Le Foll, MD, PhD

Description

The purpose of this study is to find out whether short term treatment with a
antihypertensive medication prazosin, can influence the levels of dopamine in the brain. We
will examine the levels of dopamine in the the brain using Positron Emission Tomography
(PET) and Magnetic Resonance Imaging (MRI). The study will involve three PET scans and one
MRI. One PET scan will be performed before the participants take prazosin for approximately
three weeks, and the last two PET scans will be performed after the prazosin medication
phase. We hypothesize that there will be no significant changes in dopamine levels in
healthy individuals taking prazosin.

Trial information was received from ClinicalTrials.gov and was last updated in February 2016.

Information provided to ClinicalTrials.gov by Centre for Addiction and Mental Health.